From owner-svn-src-all@freebsd.org Tue Oct 13 17:50:02 2020 Return-Path: Delivered-To: svn-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 56E764471D4; Tue, 13 Oct 2020 17:50:02 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4C9jk21d1rz40sy; Tue, 13 Oct 2020 17:50:02 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 1AF0620FEA; Tue, 13 Oct 2020 17:50:02 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 09DHo1ju028113; Tue, 13 Oct 2020 17:50:01 GMT (envelope-from mav@FreeBSD.org) Received: (from mav@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 09DHo1Yo028112; Tue, 13 Oct 2020 17:50:01 GMT (envelope-from mav@FreeBSD.org) Message-Id: <202010131750.09DHo1Yo028112@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mav set sender to mav@FreeBSD.org using -f From: Alexander Motin Date: Tue, 13 Oct 2020 17:50:01 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r366675 - stable/12/sys/kern X-SVN-Group: stable-12 X-SVN-Commit-Author: mav X-SVN-Commit-Paths: stable/12/sys/kern X-SVN-Commit-Revision: 366675 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Oct 2020 17:50:02 -0000 Author: mav Date: Tue Oct 13 17:50:01 2020 New Revision: 366675 URL: https://svnweb.freebsd.org/changeset/base/366675 Log: MFC r355083 (by rlibby): sysctl: wire old buf before output with sysctl lock Several sysctl sysctls output to a user buffer while holding a non-sleepable lock that protects the sysctl topology. They need to wire the output buffer, or else they may try to sleep on a page fault. Modified: stable/12/sys/kern/kern_sysctl.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/kern/kern_sysctl.c ============================================================================== --- stable/12/sys/kern/kern_sysctl.c Tue Oct 13 17:30:34 2020 (r366674) +++ stable/12/sys/kern/kern_sysctl.c Tue Oct 13 17:50:01 2020 (r366675) @@ -1022,12 +1022,16 @@ sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) { int *name = (int *) arg1; u_int namelen = arg2; - int error = 0; + int error; struct sysctl_oid *oid; struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; struct rm_priotracker tracker; char buf[10]; + error = sysctl_wire_old_buffer(req, 0); + if (error) + return (error); + SYSCTL_RLOCK(&tracker); while (namelen) { if (!lsp) { @@ -1264,6 +1268,10 @@ sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) struct rm_priotracker tracker; int error; + error = sysctl_wire_old_buffer(req, 0); + if (error) + return (error); + SYSCTL_RLOCK(&tracker); error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); if (error) @@ -1293,6 +1301,10 @@ sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) struct rm_priotracker tracker; int error; + error = sysctl_wire_old_buffer(req, 0); + if (error) + return (error); + SYSCTL_RLOCK(&tracker); error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); if (error) @@ -1317,6 +1329,10 @@ sysctl_sysctl_oidlabel(SYSCTL_HANDLER_ARGS) struct sysctl_oid *oid; struct rm_priotracker tracker; int error; + + error = sysctl_wire_old_buffer(req, 0); + if (error) + return (error); SYSCTL_RLOCK(&tracker); error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);